1. Field of the Invention
The present invention relates to a disk apparatus, and more particularly to a disk apparatus having an optical pickup enabled to move in a radial direction of a disk.
2. Description of the Related Art
Hitherto, various disk apparatuses each having an optical pickup enabled to move in a radial direction of a disk have been known (see, for example, JP-A-2001-101673, JP-A-2001-344789, and JP-A-1-287875).
JP-A-2001-101673 discloses a disk apparatus adapted so that a tilt-angle of an optical pickup around one of guide rails, to which the optical pickup is attached, with respect to a disk is adjusted by upwardly and downwardly moving the optical pickup along the other guide rail through the use of an adjusting screw, and that the optical pickup is moved along the two guide rails in a radial direction of the disk.
JP-A-2001-344789 discloses a disk apparatus adapted so that a tilt-angle of an optical pickup with respect to a disk is adjusted by tilting a movable chassis, to which a guide shaft for supporting the optical pickup is attached, around a predetermined axis through the use of plural gears, and that the optical pickup is moved along the guide shaft in a radial direction of the disk.
JP-A-1-287875 discloses a disk apparatus adapted so that insulating tape is wound around each of attachment parts of a shaft for supporting an optical pickup, which are attached to a frame, to there by prevent electrical noises being transmitted from the frame to the optical pickup through the shaft, and that the optical pickup is moved along the shaft in a radial direction of the disk.
FIG. 5 is a top view illustrating a disk drive portion of a related disk apparatus having an optical pickup enabled to move in a radial direction of a disk. FIG. 6 is a side view, taken from a direction of an arrow 150 shown in FIG. 5, which illustrates the disk drive portion of the related disk apparatus shown in FIG. 5. FIG. 7 is a bottom view illustrating a movable chassis of the related disk drive portion shown in FIG. 5. FIG. 8 is a sectional view illustrating the movable chassis shown in FIG. 7 taken along line 170—170 shown in FIG. 7. FIG. 9 is a sectional view illustrating the movable chassis shown in FIG. 7 taken along line 180—180 shown in FIG. 7.
Referring to FIGS. 5 and 6, in a disk drive portion of a related disk apparatus, a chassis 101 formed of a metallic plate material is provided at the bottom thereof. A disk motor 102, on which a disk is placed, for rotating the disk is fixedly mounted on this chassis 101. A movable chassis 101a formed of a metallic plate material is provided above the chassis 101 in such a way as to be spaced by a predetermined distance from the chassis 101. As shown in FIGS. 5 and 7, a first metallic shaft 103a and a second metallic shaft 103b are attached to this movable chassis 101a in such a manner as to be parallel with each other.
An optical pickup 103 is supported by the first shaft 103a and the second shaft 103b in such a way as to move in a direction of an arrow A shown in FIG. 5 (that is, in a radial direction of a disk). As shown in FIGS. 5 and 7, a displacement motor 105 for displacing the optical pickup 104 is attached to the bottom surface of the movable chassis 101a. This displacement motor 105 has a drive shaft 105a on which a gear is formed. The optical pickup 104 is engaged with the drive shaft 105a of this displacement motor 105.
One of end portions of the first shaft 103a is attached to a resin shaft support member 106 provided on the bottom surface of the movable chassis 101a, as shown in FIG. 7. The other end portion of the first shaft 103a is fixedly attached to a first shaft fixing resin member 106, which is provided on the bottom surface of the movable chassis 101a, by a metallic fixing member 113, as shown in FIGS. 7 and 8. The metallic fixing member 113 is screwed to the metallic chassis 101a by the metallic screw 114.
Both end portions of the second shaft 103b are fixedly attached to a second shaft fixing resin member 106b provided on the bottom surface of the movable chassis 101a by a metallic washer 115, as shown in FIGS. 7 and 9. The metallic washer 115 is screwed to the metallic movable chassis 101a together with the second shaft fixing member 106b by a metallic screw 116.
A support projection member 117 having a semispherical end portion is attached to the bottom surface of an end portion that the movable chassis 101a has at a side, at which the first shaft 103a is installed, as illustrated in FIGS. 5 to 7. A support receiving member 118 having a conical (or spherical) support surface is provided at a place, which corresponds to the support projection member 117, in the chassis 101, as shown in FIG. 6. The semispherical end portion of the support projection member 117 is supported by the support receiving member 118 in such a way as to move by simultaneously contacting the spherical support surface of the support receiving member 118. A pressing member 119 constituted by a leaf spring is attached to the chassis 101 in such a manner as to downwardly pressing the support projection member 117 attached to the movable chassis 101a. This pressing member 119 is provided so as to prevent the support projection member 117 from the support receiving member 118.
A first tilting mechanism 107a is provided at an end portion that the movable chassis 101 has at a side at which the second shaft 103b is installed, as shown in FIG. 5. This first tilting mechanism 107 is provided so as to tilt the movable chassis 101a so that the end portion of the movable chassis 101a upwardly and downwardly moves around the support projection member 117. The first tilting mechanism 107a has a projection member 120a, a projection receiving member 120b, a holder 120c, and an adjusting screw (not shown).
An end portion of the projection member 120a is hemispherically formed and attached to the bottom surface of the movable chassis 101a in such a way as to downwardly protrude therefrom. The projection receiving member 120b is provided in such a way as to support the projection member 120a from below so that the projection member 120a is movable. The holder 120c is attached to the chassis 101 and provided in such a way as to support the projection receiving member 120b so that the projection receiving member 120b can upwardly and downwardly move. The adjusting screw (not shown) is engaged with the chassis 101 and provided in such a way as to abut against the bottom surface of the projection receiving member 120b. Also, the adjusting screw (not shown) is provided in such a way as to be able to upwardly and downwardly move by being turned.
As shown in FIG. 5, a hook member 121 is provided in the vicinity of each of the first tilting mechanism 107a of the movable chassis 101a and the support projection member 117. Hook receiving members 122, with which the hook members 121 engage, are provided at places corresponding to the hook members 121 of the chassis 101, respectively. Each of these hook receiving members 122 is shaped so that the hook member 121 can engage therewith in such a way as to have a predetermined play therefrom. The hook member 121 and the hook receiving member 122 prevent the distance between the movable chassis 101a and the chassis 101 from becoming equal to or more than a predetermined distance.
As shown in FIGS. 5 and 6, a second tilting mechanism 107b is provided in the disk drive portion. This second tilting mechanism 107b has a tilt motor 123a, a drive transmission gear 123b, an intermediate gear 123c, a cam gear 123d, a cam-gear projection member 123e, and a spring member 123f. The tilt motor 123a is fixedly attached to the chassis 101. The drive transmission gear 123b is attached to a drive shaft of the tilt motor 123a. The intermediate gear 123c meshes, with the drive transmission gear 123b and the cam gear 123d. A cam portion 123g having a predetermined slope shape is formed on the top surface of the cam gear 123d, as shown in FIG. 6. The cam gear projection member 123e is attached to the movable chassis 101g and provided in such a way as to abut against the cam portion 123g. The spring member 123f is attached to the chassis 101 and pushes the cam gear projection member 123e against the cam portion 123g of the cam gear 123d. 
Next, an operation of the first tilting mechanism 107a of the disk drive portion of the related disk apparatus is described hereinbelow by referring to FIG. 5. First, the adjusting screw (not shown) abutting against the bottom surface of the projection member 120a is turned. Thus, the adjusting screw (not shown) is moved upwardly or downwardly. This is accompanied by an upward or downward movement of the projection receiving member 120b. Thus, an end portion of the movable chassis 101a, at which the projection member 120a is provided, is moved upwardly or downwardly. Consequently, the movable chassis 101a is upwardly or downwardly tilted around the support projection member 117.
An operation of the second tilting mechanism 107b of the disk drive portion is described hereinbelow by referring to FIGS. 5 and 6. The cam gear 123d is turned by transmitting drive from the tilt motor 123a thereto through the drive transmission gear 123b and the intermediate gear 123c. When the cam gear 123d is turned, the cam gear projection member 123e is upwardly and downwardly moved along the slope shape of the cam portion 123g. Consequently, the movable chassis 101a, on which the cam gear projection member 123e is provided, is upwardly or downwardly tilted around the support projection member 117 and the projection member 120a. 